Sorry Woody, I think you've stumped me on this one!
At first I thought the metal collars were from the parking brake cross bar pivots,but they look a little small for that! headscratch
You have my sympathy. Been there,done that!
Hopefully someone else will chime in!

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.